#include <bits/stdc++.h>
using namespace std;
const int N = 2e3+10;
double d[N][N];
int n, m, k; double p1, p2, p3, p4, p12, p14, p13;

double dfs(int i, int j){
    if(j == 1) return 0;
    if(j <= k) return p12*dfs(i, j-1) + p13*d[i-1][j-1] + p14;
    if(j > k)  return p12*dfs(i, j-1) + p13*d[i-1][j-1];
}

int main() {
    cin >> n >> m >> k >> p1 >> p2 >> p3 >> p4;
    p12 = p2/(1-p1), p14 = p4/(1-p1), p13 = p3/(1-p1);
    d[1][1] = p4/(1-p1-p2);
    for (int i = 2; i <= n; ++i) {
        d[i][1] = p12*dfs(i, i) + p14;
        d[i][1] /= (1-pow(p12, i));
        for (int j = 2; j <= i; ++j) {
            if(j <= k) d[i][j] = p12*d[i][j-1] + p13*d[i-1][j-1] + p14;
            else d[i][j] = p12*d[i][j-1] + p13*d[i-1][j-1];
        }
    }

    if(p4==0) printf("%.5f", 1);
    else printf("%.5f", d[n][m]);
    return 0;
}